diff --git a/appveyor.yml b/appveyor.yml
index d0d8fadff1..28f5221cf5 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -89,6 +89,8 @@ for:
     - nmake install-nodoc
     - \usr\bin\ruby -v -e "p :locale => Encoding.find('locale'), :filesystem => Encoding.find('filesystem')"
   test_script:
+    # make sure mingw dll's are not in path, but allow *nix exe's in C:\msys64\usr\bin
+    - SET PATH=\usr\local\bin;%ruby_path%\bin;%PATH%;C:\msys64\usr\bin
     - set /a JOBS=%NUMBER_OF_PROCESSORS%
     - nmake -l "TESTOPTS=-v -q" btest
     - nmake -l "TESTOPTS=-v -q" test-basic